Indonesia said Thursday it was unclear why the United States recently issued a travel advisory for American citizens in the city of Surabaya.

President Joko Widodo, widely known as Jokowi, said there was nothing to worry about.

"I have not received any information on threats of a security breach," he said. "That means we are safe. Don’t be too zealous."

Foreign Minister Retno Lestari Marsudi said she was aware of the travel advisory but didn't know the reason for it.

"We have communicated with the U.S. Embassy [in Jakarta] to explain to us what was the basis in issuing the security alert, and they said they have some information," she said. "However, they didn’t convey that information to us."

At a State Department briefing in Washington on Thursday, spokeswoman Jen Psaki did not provide details of the information that prompted the alert. But she did say it was unrelated to the recent AirAsia flight that crashed after taking off from Surabaya.

"We have no knowledge of any connection between this threat and the AirAsia flight," Psaki said. "So this was separate information that we wanted to put out to the public there."

The travel alert said the U.S. had been made aware of a potential threat against U.S.-associated hotels and banks in Surabaya. Further details of the threat were not disclosed.

Indonesia has suffered terror attacks in the past, including a massive bombing in Bali more than a decade ago. Recently, officials in Jakarta have said they are trying to combat Islamic State recruitment of its citizens.

This report was produced in collaboration with the VOA Indonesian service. Pam Dockins contributed from the State Department in Washington.